Effects of four-weeks porcine-collagen hydrolysate consumption on glucose concentrations, glycemic variability, and fasting/postprandial cardiometabolic risk markers in men and women with overweight or obesity: A randomized, controlled trial.

BACKGROUND

Different collagen hydrolysate sources have reduced fasting glucose concentrations. Although porcine-derived collagen hydrolysate predicts in vitro the highest potency for improving glucose metabolism, these effects have not been studied in humans.

AIM

To evaluate the effects of porcine-derived collagen hydrolysate on continuously monitored glucose concentrations in real-life conditions in individuals with overweight/obesity. Additionally, postprandial responses following a mixed meal test were examined.

METHODS

Fifty-six men and women participated in this randomized placebo-controlled parallel trial. After a two-week run-in period, participants consumed daily for four weeks 10 g porcine-derived collagen hydrolysate or placebo (erythritol). The primary outcome parameter was the interstitial glucose area under the curve (AUC) during daytime (07:00 to 22:00) measured during three consecutive days. In addition, glycemic variability (GV) was quantified. For this, a continuous glucose monitor (Freestyle Libre ProiQ, Wiesbaden, Germany) was used at the end of the run-in and intervention periods. Postprandial glucose, insulin, and triacylglycerol concentrations were also evaluated after a mixed meal tolerance test. Furthermore, fasting glucose, insulin, hemoglobin A1c (HbA1c), homeostatic model assessment for insulin resistance (HOMA-IR), HOMA of β-cell function (HOMA-β), and triacylglycerol changes were analyzed. Physical activity profiles and dietary intakes were monitored to exclude confounding by these lifestyle factors.

RESULTS

Collagen hydrolysate consumption did not significantly affect daytime interstitial glucose AUC concentrations (95%CI for the effect size: -5.1, 30.0 mmol/(L∗h); p-value = 0.159), but increased several GV metrics: standard deviation (95%CI: 0.0, 0.2 mmol/L; p-value = 0.011), continuous overall net glycemic action (CONGA-4) (95%CI: 0.1, 0.4 mmol/L; p-value = 0.015), coefficient of variation (95%CI: 0.1, 3.0 %; p-value = 0.036), M-value (95%CI: 0.2, 1.8; p-value = 0.036), and mean amplitude of glycemic excursions (MAGE) (95%CI: 0.2, 1.8 mmol/L; p-value = 0.036). Furthermore, the postprandial glucose AUC after the mixed meal test significantly increased (95%CI: 0, 103 mmol/L∗4-h; p-value = 0.049), as well as fasting insulin concentrations (p-value = 0.005), HOMA-IR (p-value = 0.008), and HOMA-β (p-value = 0.009). Other parameters, anthropometrics, physical activity, and energy/nutrient intakes were not significantly changed.

CONCLUSION

Four-week collagen hydrolysate intake did not change free-living glucose concentrations, but increased GV, postprandial glucose AUC, fasting insulin, HOMA-IR, and HOMA-β. However, these changes were small with limited clinical relevance. Therefore, it can be concluded that this porcine-derived collagen hydrolysate does not improve glucose metabolism or other cardiometabolic risk markers.

CLINICAL TRIAL REGISTRATION

This clinical trial was registered in November 2021 as NCT05282641.